1. Field of the Invention
This invention relates to a process for the production of polyol ethers by catalytic reaction of mixtures of polyols and carbonyl compounds with hydrogen at elevated temperatures and under elevated pressure.
2. Statement of Related Art
Ethers of polyols, for example glycerol ethers, are surface-active substances which have excellent detergent properties and which may be used, for example, as wetting agents (U.S. Pat. No. 2,932,670), emulsifiers (DE 11 00 035 A1)] or lime soap dispersants (U.S. Pat. No. 3,350,460).
Polyol ethers are generally produced by WILLIAMSON'S ether synthesis. In this process, polyols, for example glycerol, are reacted with alkyl halides in the presence of strong bases. According to DE-PS 615 171, alkali metal salts of alkyl sulfates may be used instead of the alkyl halides.
However, the known processes mentioned above all have the disadvantage that the production of the polyol ethers is accompanied by the accumulation of salts, for example potassium chloride or sodium sulfate, which cannot remain in the product, but instead have to be removed--in some cases with considerable effort.
Another serious disadvantage is that these salts are by no means pure, but instead are contaminated with significant quantities of product. Accordingly, the disposal of these waste materials is extremely expensive and adversely affects the profitability of the process.
Accordingly, the problem addressed by the present invention was to provide a process for the production of polyol ethers which would be free from the disadvantages mentioned above.